The GNU Privacy Guard (GnuPG) enables people to securely exchange messages and to secure files with both privacy and strong authentication. GnuPG is a free software replacement for the PGP suite of cryptographic software.

TrueCrypt is a free open source on-the-fly encryption (OTFE) program for Microsoft Windows XP/2000/2003 and Linux. It allows one to create a virtual encrypted disk within a file and then mount it as a real disk

The Social Source Commons is a “knowledge commons” that provides users with: a directory of software applications; links to relevant documentation, localization tools, services, user reviews; and a place to request tools/features.